Heating apparatus



Auge 15, 1950 v. F. PARRY 2,518,490

HEATING APPARATUS ,gig 1.

Aug 15, 1950 v. F. PARRY 2,518,490

HEATING APPARATUS mveNToR ,.ZLQ VERNON F. PARRY,

Aug. 15, 1950 v. F. PARRY HEATING APPARATUS original 'Filed April zo. 1945 4 Sheets-Sheet 3 INVENTOR VERNON F. PARRY,

Aug. 15,1950 v. F. PARRY 2,518,490

` 'HEATING APPARATUS' Griginal Filed April 20, 1945 4 Sheets-Sheet 4 INVENTOR VERNON F. PARRY,

patented ug. ES, Q

UNITED STATES lerili.NT ICE HEATING .LiPARA'IUSy Vernon F.. Parry, Golden, Colo. original Vapplication Aprilyzo, 1945, serf1a1 No; 589,450. Divided andihis, applicationctober 7,1946,seria1N0.7o1,sss l a claims., (c1. zegels.) (Granted under the act ofv March 3, 1883 Vas 1` The invention described herein may be manufactured and used Vby or for the Government of the United States Afor `governmental purposes Without the `payment to me of any royalty thereon in accordance with the provisions of the Act of April 30, 1928 (Ch. 460, 45 Stat. L. 467) This invention relates to chemical reaction apparatus and more` particularly to suitable devices for carrying out.endothermic chemicalreactions involvingsolid andgaseous or vaporous materials. Still more particularly, this invention relates to processes for the production of synthesis gas and fuel gasfrom subbituminous coal or other'noncaking or non-agglomerating carbonaceous matef rials ina vertically ranging externally heated annular retort.

Heretofore in the fuel converting art large reaction vessels requiring heat transfer at "high temperatures, .have been made of refractory fire brick and heated by gas or oil-'fired ovens. Such refractory 'fire-brick settings have low thermal conductivity and. @they r,transmit heat relatively slowly compared with the heat transfer which may be transmitted through..metals.` `In theheating of metallic reaction vessels, troubles are usually encountered from'localoverheating which causes excessive corrosion, unequal expansion, and shortl usefiillife of the metal. It'has now been found that by employing the special heating system herein described,..alloy reaction vessels can be heated safely and 'uniformlyin controlled atmosphere, .and their useful life extended through a longperiod fof `continuous operation.

An important object of i thev invention is the provision of a suitable combustion system, which employs impro'vedmeans of recuperation, .for heating the vertically ranging externally heated retort, `and an improved air-cooledfan for recirculation of products of combustion. This heating system makes it possible to conduct the several processes described herein at .maximum -.-thermal eiliciency. `Other objects of .the invention. will be apparent or will appear -as the ensuing description proceed`s.`

In the following description, it should be understood that the term gaseous includes .materials' Which are vapors at thetemperatures encountered, suc'h as for example, steam, oil vapors, and similar materials. Furthermore the terms non-caking nonfagglomerating, or non-coking are associated with and define `a material Pthat does notswell or fuse to destroy its ability to move by gravity asa relatively free-flowing material. Inldescribing ithe apparatus 'ofjthis invention, the

amended April 30, 1922?;1370 O." G. "757) gasicati'onof lignite iorsubebiturninous coal,` but the inventionis .110@ limited thereto as will be 'apparent. .l i l The reader ywill` appreciate.; theimproyement in the artan'd 'efficiency of easincaton of fuel made possible .by this invention when he considers the brief compa'son'cited jherewithf y1n present commercial .processes for, the manu* facture of synthesisgas from, coke, as practiced brlaiee H.,i,r.l,dus tr es. orieltongof. higlir'rank bituminous 'poking coal of 13,500 B tl 1x. per pound, after coking in aV coke. oven, will y make about 35,000 cubic feet of synthesis gas., The conversion requires2 steps: (a) Cokig in the coke ovenby intermittent operation; and "(blga'siiication in a watergas machineV by intermittentblasting with air .and steam. In the continuous process comprising this invention one ton' of natural subbituminous .coal containing` about 22 percent Water andhaving `a heating value of only 9,300 B. t,v u. .per pound, is gasied continuously to produce 45,000. cubic feet of net synthesis gas in a 1s1ing1e,stage process i that, Operates automatica y.

In order to accomplish 'the high conversion efiiciency, ranging from 60 to 7 5, percent or -higher, .the heat saving devices andthe counter-current. heat exchange principles outlined, herein have vbeen invented.

In the accompanying drawings: .Figure 1 is a View partlyin section .and partly diagrammatic, `showing a Iverticallyranging annular reactiodapparatus 'havingan external heating chamber and aY recuperator,V ,associated therewith.

Figure '2 .isa view, partly 'in section and partly diagrammatic, rshowing Va generating unit and thereeycling apparatus.

Figures 3,` land'f show sectional views of Vthe brickwork, gas firing ports, air ductsrand comdescriptionfwill bexuirected `v`principally to the theair-cooled fan,

temperature increases. The products of reactionV are removed from the interior of the'annular reaction zone and give up a substantialfportion of their sensible heat to incoming reactants. Solid materials not combined with'vreactants in the upper zone are then directeddownwardly where they contact cooling gases which transfer` heat from the solids back toward the center ofA the system, and the spent solids are discarded at a low temperature. Thus, heat for carrying out the gasification reactions is retained near the centerof the system, and products leave at low temperature YwhichV insures ,high efficiency. In gasif'y'in'g un-dried sub-bituminousA coal, up to 95,00() gross cubic feet of water gas is obtained perton of coaltreated. The'spent residue containsonly 2 to 10 percent of, the carbon originally present in the rawcoal charged. Part of the gas mademay be directed'back for heating the reaction ,vessel or suitable producergas may be generated from spent solids to supply heat for the reactionsl",` The combustion system is arranged to return heat to Ythe high-temperature Zone andto recover substantially all the heat from the evolved gases;y Y d Fora practical embodiment of the invention, and referring lnow to the drawings, ,an elongated vessel 56 whichhmay be' vertically mountedas shown, `is providedlnearV its` upper end 'with a suitable device foreeding solid materials later to ,be described, and is closed atits lower end by asuitable closureclevice vforming a part of the supporting meansfor 'the vessel 56. As shown in, Figuresfland 2, tliieTclosure device is'fan inverted cohicalann'uluslB". The vessel 56 may hayeany desired crosssectional form, but it is preferably made circularin "order to simplify construction, Connecting "the conical discharge anrfnilusM |136 and th'eulvessel- 55 is an expansion `joint 'seal' 55,'"which`may be of the flangedv or ring type. The conicalV annulus'lt is supported bysuitable adjustable' resilient mounts 49 or 445a which may takethe form of `springs or` hydraulic jacksv (not shown) ladapted to exert an upward pressure against the force of gravity and to maintain any desired stress condition inV the vessel. For many chemical reactions involvingfso'lid and'Y 'gaseousfor v aporous reactants, "it has been found that aplurality of internal heatexchange devices mounted in the common elongated vessel 56p rovid es a superior annular reaction apparatus, particularly where it is desired' to carry out a; multiple-stage 'reaction' involving concurrent treatment of'solids andgases in a iirst annular reaction 'zonel'and countercurrent treatment of solids'and gases in' a second' annular ,reaction zone. Asuitable form of apparatus particularly shown in Figures l and 2,'comprises a cylindrical annulus 53 occupyingethe upper portion of the elongatedV vesself56 aligned therein and surmountin'g, "but spaced from "a" lower cylindrical annulus 36. 1As"shown, the flower cylindrical 'annulus 36 is capped by a conical' closure |34. The wall of the lower cylindrical :annulus- S5 Vdefines Withethe"wall'oftlie'elongated vessel 56 2.? Second or lower reaction zonejiuwhich solids VV'ga'.ses'or' vapors may be suitably introduced by may react with or evolve gases or vapors. The bottoms of both the annulus 58 and the annulus 36 are open to permit free gas passage. The lower portion of annulus 58 and the conical closure |34 of the annulus 35 dene a throat 34 for permittingescape of gases from the reaction zones 33 and 35 into heat exchange zone 40.

Optionally, suitable means for measuring the temperatures prevalent in the annular reaction zone 35 may be provided, and as shown, a temperature responsive device I4 may be suitably positioned .to indicate reaction temperatures. Where it is desired to introduce gases or Vapor into the lower he-at'exchange zone |35 or into the'interior of Ythe cylindrical annulus 36, such way Aof'anl inlet pipe 31.

Associated with the elongated vessel 56 are novel heating means for supplying necessary endothermic heat to carry out the reactions taking place in the annular reaction zones 33, 35. As shown inFigure'Z, such means may take the form"of -acornbustion chamber having ,an outer casing |39.associated with a recuperator having an outer casing I6 for recovering heat from combustion'gases, an exhaust fan |43, a fresh air duct 21 oralternately l5, and suitable adjustable means including awvalve |46 for reeirculating a proportion of ilue gases or P. O. C. (products of combustion) to the combustion chamber as a tempering medium for controlling flame temperatures in the combustion Zone 24heating the vessel 56. j" t The combustion chamber outer casing |39 `(Figures 1` and 2) has'aY suitable base structure `|1|' and bottom vclosure |10 mounted therein, embracing the vessel 56 in a gas-tight lsliding fit. The top ofthe casing |39 has a cap '|40 embracing thev upper portion Yof the vessel'56 in gas-tight sealing engagement. therewith.V 'The casing 13e is provided with'an insulating refractory lining 51 through which extend a series of tangential burnerports 2;'2l,"and 22 sh'own in' detail in Figures',4 4' 'and' 5. The'tan'gential* burner ports 2li,` 2|, and'22'are `mounted in the outer casing |39 at diierent levels 'anddirect burning fuel into the combustion zone 24 around the vessel 56. A series of"vertically rangingY gas passage ducts I9 identified by ducts A, B, C, D, E, F, G, H, I, J, K and-'L of Figure'are formed in'thelining 51 and 'supply a preheated mixture of Yair 'and recirculated product soi combustion (P. O. C.) to

Ytangential burner ports 2B, 2 I, and 22, In Figures 3 and 4, an arrangement of the tangential burner ports at two levels is indicated.A In Figure 3 which represents across section; through baille 53 lat 'C -C inv Figure l," an'arrangement of twelve vertical ducts |`9 is indicated by clock-wise lettering from A' to'L; VSuch'ducts aresuitable for firing amedium sizedcombustion furnace. In a larger Yfurnace a plurality ofducts would be providedto supply preheated air and Yproducts of combustion at different levels as the furnace incre-ases in' height, having about the same distribution at each level as that indicated'in Figure 4. Duets |j9 may be of any suitable shape'and sizeV to Aprovide for required gas-flow; Referring to Figure 2,*the refractory insulating material'l outlining the combustion zone 24 within the outer casing |39, isV preferably madeV of' light-weight insulating refractory key brick but. suitable plastic insulating refractories that can be cast-in place Amay be used'. A gas passage manifold I1 is formed inthelining 5 1-near thegupper end thereof and provides a; common source of supply orrfromsthe top offthe refractory .bottom` lining upwardly toward burner-.ports `2| .and embraces the vessel .'56 .to protect it from-- excessive .local heatiiog..v A- horizontally ranging de'lecting': bale B3n/.is located in the. aupperzportion ofthe' combustion zone' 24-ifbelow a discharge.y flue 25itoircause combustion? :ga-scsi .to :xtra-vel 4completely around thezyess'ela. v i A f '.Af. ilue 251=in the vcasing 8 l Lconn'ects l the upper portion of the combustion Zone 24 abovethe baffle 53 with the recuperator andeservestto? conduct combustion gases from the combustionzone 26S tothe recuperator as shown in' Figures l and 2.

The :recuperator comprises an louter casing I6 mounted uponza basezf|62 forming a bottom closure suitably supported bymeansnot shown,` and a cap 16| forming-an upper closure. 'The outer casing. .I 6 fis provided. v-Jith a suitable. insulating refractory lining |B3..to: 'minimize heat losses. Vertically, disposed inthecasing '.IS is a suitable tube bundle It support'edlby an upper tube sheet I'S'l and a lower tubesheet |68 (Figure 2). Suitable horizontal derlecting. baflies |542 are disposed inside thecasing -.|6.1.about.ithe tube bundle |6 to. provide for an elongatedlaswpassage traveling about and through the tube 'bundlell products of combustion-issuing from `thecombustiony zone Zathrough Vthehue` 25. enter the recuperator belowthe vupper tube sheet.` |61 and paSsdOWnWardlyv aboutthe tubebundle It (Figure 3). Theyare rernovedifromL the recuperator through a `liue Zifafter giving: up theirheat anduarev thencefpassed throughtanexhaust fan |53 into=.a.fstaclr junetureffcasing v|63. A lower headerl-ES is 'formedin-thelower .portion-of the casing I t. andis :adapted to distribute `incoming air andrP.' O. C'. ythroughlthe"interior ot thetube bundle itt. f nnwupperheader |64 -is' formed by the .uppertube sheetl @1.61. and passes'iiesh air and'reCirCulated products of combustion into the inlet'duct '156; Thestackjuncture 'casing |63, upon which is mounted the stackvSZ, is provided with 'alistack valve 1| 45. Thecasing |69 also has aV .valve |45' through which a controlled proportion'o'ffproducts of combustion can -be recirculated to .the systemi YConnecting the fresh air inlet 27 and the stack juncture |69 is a juncture 21o for admixingrecirculated liuc gases with fresh combustion ain lower header H55 and the juncture 21a i's a-iduct 28 through. .which fresh air and. acontrolled pro portion of combustion products may be sent .throu'ghithe tube bundle ofthe recuperator.

v"'ptionally, suitable vmeans for introducing air into' the systemv is through inlet duct l5 forming a junction with-duct Y2-inadvance of exhaust'v fan |113'. `Fresh air introduced atfthis point serves to cool the fan=blades-a rIhereshair and P. O. C. mixture handled by the fan is circulated back through the system through duct 28, andpart is'discarded tothe lstack 52 by regulation -of valves e5 and |126.

In the operation of the heating system or device associated with and forming a part of the reaction apparatus, fuel from gas header 5| is burned at the burners 20, 2 l, and 22 in controlled The f.;

Connecting 'tliel recuperator Y amounts. The' highlyfheated products: ofsc'oni bustionascend and swirl about the vessel*r 156. They are. then directed" past `*the horizontally ranginglbaflefS .through the flue `25.into. the recuperator outer :casing i6. In the recupierator casing lthe products oi combustion pass 'downwardly Lin indirect countercurrent heat exchange vrelationship with incoming tempered airs-Land P; lOiC., being directed through the reouperator in-fan elongated path by the ballies |62, yandfgive up la substantial portion of their sensibleheat; Issuing fromthe recuperator near the lower-.por` tion thereof, the partially cooled products of com-i, bustionrpass by way` of the flue 26 through the fan |43 into, respectively, the staclr52 and the fresh air duct 2"! in accordance with the arrangement ofthe gas-flow regulating valves |45 and |461 @Fresh air or-other source of oxygenvfor combustion entersV through thefa'irf duct' 21,1-1is mixed with a predetermi-nedfquantity ofcombustion products at the :juncture Ela, and the diluted orltempered air then passes through the -ue28 back through the recuperator Iii and into the combustion chamber manifold Il. i Optionally,

J `fre'shlair may-be introduced into vthe system lthrougl'lf'port' 'E5 in duct vZijust in frontl of fthe fan as previously described. From thel manifold ll the tempered and partially preheated air passes downwardly through the metering valves l into'the pren-eating ducts IQ and thence to the burners-20,- 2|, and 22, `in` suitably metered amounts. As shown, the preheating ducts'l9 are in indirect countercurrent heat exchange relationship with the combustion zone 24 and the contained upwardly-moving products of cornbus tion. By this arrangement and correlationI of parts, a very desirable uniformly-controlled heating is .secured for theelongated vessel 56 andthe heating is carried out with very high thermal efliciency.

Optionally another form of the heating system is illustrated in Figures 6, 7 and 8. The combustion system in casing |39 is the same as that previously described but the recuperator is omitted and replaced by aspecially built fan for recircu1a1 tion of highly heated `products of combustion. The .fan [B .is mounted on .a platform |93 supported by brackets |9'l and connected to the shell casing |353.l rIt is constructed of material adapted to withstand high temperatures and is insulated by a suitable insulating layer |955. Aplurality of hollow blades |93 are mounted on a hollow shaft |88 Vextending into the fan casing 2ML The hollow s lia'ft '|88 iscarried by suitable outboard bearings |95 which are placed away.A from theheatlorra suitable mounting. The shaft'extends into an air junctionbox it and is driven by pulley |96, connected to a suitable prime mover (not shown).

In the operation of this optional heating sys' tem or device associated with and forming `a part` offthe reaction apparatus (Figure 6), fuel is burned at the tangential burners 2&3, 2|, and 22 in controlled amounts. Ihe highly `heated prod--k ucts of combustion ascend and swirl about the vessel 5t and are directed past the horizontal r into the hollow fan blades ISB, Where it emerges asienta through ports |89, preferably located on the trailing edge of the blades, and mixes with products of combustion. The fresh cooling air traveling at high speed through the hollow shaft and blades cools the metal and allows the fan to operate in the envelope of highly heated products of combustion. The discarded products of combustion passing through duct 92 enter a countercurrent heat exchange device |49, where they give up the major portion of their heat to gases or vapors used in the reactions carried out in the reaction vessel 56. The gases or vapors are introduced into the heat exchange device |139 through yport H9, and they leave through port ISD. Optionally the discarded products of combustion may be usedfor predrying or roasting solids.

As a further example of the operation of the process of complete gasification of subbituminous coal in the double annulus system illustrated in Figure 2, the following operating data from a test in a pilot plant are cited:

Coal charged, pounds per hour Moisture in coal as charged, percent Ash in coal as charged, percent. Refuse out bottom of retort, pounds Ash content of refuse, percent Tar or oil formed Gas made, cubic feet per hour SGC Analysis of gas made:

, Carbon dioxide, percent. 1. llluminants, percent Carbon monoxide, percen Hydrogen, percent Methane, percent Nitrogen Heating value of gas, B. t. u. per cubic foot, observed Specific gravity of gas Steam used in zone 33, pounds per hour Steam used in zone 35, pounds per hour Steam not decomposed, pounds per hour.

Net heat used in combustion chamber 24 B. t. u. per hour. Products of combustion recirculated cu. it. per hour 5, 560

Temperature of bottom of combustion chamber at (l) F 2050 Temperature of middle of combustion chamber at (2) F 1900 Temperature of top of combustion chamber at (3) F 1530 Temperature leaving combustion chamber at (4) F 1390 Temperature of P. O. C. leaving recuperator (5) F` 755 Teilliiperature of air and P. O. C. returned to recuperator (7) 385 Temperature of air and P. O. 0. leaving recuperator (8) F 1000 Temperature of products leaving retort (l2) F 770 The above data represent average of 2li-hour operation during a test lasting about 100 hours.`

Other processes employing the annular retort principle While the apparatus of this invention as previously particularly described relates to the gasification and distillation of subbituminous coal or lignite and the recovery of oil from oilbearing shale, nevertheless, the same reaction conditions and equipment can be utilized in the destructive distillation of any non-caking carbonaceous material such as for example noncoking or non-caking subbituminous or bituminous coals. The apparatus of this invention as generally applicable to the gasification of lower rank fuels where the fuels employed as feed materials contain more than 10 percent by weight oxygen on a moisture and ash-free basis.

vIt will be apparent from the foregoing description, there Vhas been provided a means for carrying out reactions in a novel and desirable manner. A very excellent heat economy is secured by this invention. Heat transfer between an exterior source of heat, and a solid reactant is very greatlysuperior in my invention to any previously known device for accomplishing this purpose. Furthermore, the device is eminently suited to construction materials capable of withstanding the relatively high temperature often encountered in the endothermic reactions described, thus permitting a very long equipment life. For example, the reaction vessel and the heat interchange elements may be made of corrosion-resistant chrome-nickle steels, alone or provided with a protective coating of chromium, or the like. As the apparatus is. susceptible of construction in generally circular or cylindrical shapes, the usual expansion problems normally encountered are largely or completely obviated.

This application is a division of my application,` Serial No. 589,450, filed April 20, 1945.

Since many apparently widely differing embodiments of the invention will occur to one skilled in the art, various changes may be made in the method and means described and shown, without departing from the spirit and scope of this invention.

What is claimed is:

1. In apparatus for the controlled heating of an elongated vessel, the combination with such a vessel of a refractory housing enveloping said vessel but spaced apart therefrom to define a combustion zone, a plurality of axially spaced burner ports in said housing for admitting fluid fuel for combustion in said Zone, a conduit in said housing communicating with each burner port for supplying attenuated air to each burner, a flue for removing combustion gases from said housing, a fan-having an inlet for supplying air to said conduits in communication therewith, and means connected with said flue and said fan inlet for recycling a controlled proportion of said combustion gases to said fan inlet.

2. Invapparatus for the controlled heating of an elongated vessel, the combination with such a vessel of a refractory housing enveloping said vesselbut spaced apart therefrom to define a combustion zone, a plurality of axially spaced burner ports in said housing for admitting fluid fuel forV combustion in said zone, a conduit in said housing communicating with each burner port for` supplying attenuated air to each burner, a flue for removing combustion gases from said housing, a fan having an inlet for supplying air to said conduits in communication therewith, means connected with said flue and said fan inlet for recycling a controlled proportion of said combustion gases to said fan inlet, and a recuperator between said fan and said flue, connected both to said fan inlet and said conduit, for transferring heat from said combustion gases to the mixture of air and combustion gases.

' VER-NON F. PARRY.

REFERENCES CITED The following references are of record in the le'of this patent:

GreatBritain Nov. 16, 1936 

